Wetlands exert major impacts on global biogeochemistry, hydrology, and biological diversity. The extent and seasonal, interannual, and decadal variation of inundated wetland area play key roles in ecosystem dynamics. Wetlands contribute approximately one fourth of the total methane annually emitted to the atmosphere and are identified as the primary contributor to interannual variations in the growth rate of atmospheric methane concentrations.

Climate change is projected to have a pronounced effect on global wetlands through alterations in hydrologic regimes, with some changes already evident. In turn, climate-driven and anthropogenic changes to tropical and boreal peatlands have the potential to create significant feedbacks through release of large pools of soil carbon and effects on methanogenesis. Despite the importance of these environments in the global cycling of carbon and water and to current and future climate, the extent and dynamics of global wetlands remain poorly characterized and modeled, primaily because of the scarcity of suitable regional-to-global remote-sensing data for characterizing their distribution and dynamics.

We will construct an Earth System Data Record of Inundated Wetlands (IW-ESDR) to facilitate investigations on the role of inundated wetlands in climate, biogeochemistry, hydrology, and biodiversity. The IW-ESDR will enable advances in understanding the role of wetlands in:

global cycling of methane, carbon dioxide (CO2) and water,

interactions among climate, greenhouse-gas emissions, and water exchange,

climate change effects and feedbacks,

maintaining ecological health and biodiversity of critical habitats, and

management of water resources for long-term sustainability.

We will employ mature algorithms to produce two complementary ESDR components:

Global monthly mapping of inundation extent at ~25 km resolution for the period 1992-2009, derived from multiple satellite observations.

Comparison and validation of these data sets will ensure self-consistency within the ESDR. Accuracy assessment of the fine-scale regional wetlands data sets will take advantage of high-resolution wetlands maps to be made available through collaborators.

The IW-ESDR will provide the first accurate, consistent and comprehensive global-scale data set of wetland inundation and vegetation, including continental-scale multitemporal and multi-year monthly inundation dynamics at multiple scales. Each component of the ESDR has been designed to facilitate a range of studies by addressing critical gaps in data and understanding of the role of inundated wetlands in important cycles and processes.

The global, monthly ~25 km inundation data set, spanning almost two decades, represents a unique, comprehensive source of quantitative information to support analyses and modeling of wetlands in global cycling of methane (CH4), CO2 and water, and in simulating interactions among climate, greenhouse-gas emissions, and water exchange for past, current and future time periods.

The IW-ESDR data set will be maintained, archived and available to the science community through integrated web sites at JPL, the University of Montana Numerical Terradynamic Simulation Group (NTSG), Earth Science Information Partners (ESIP), and the Japan Aerospace Exploration Agency. Web-based tools will be provided to support user access to ESDR components. Distribution of thematic mosaics and assembly of user-defined mosaics will be supported.